Dental mallet and plugger.



W. G. THOMAS.

DENTAL MALLET AND PLUGGBR.

APPLICATION FILED MAY 12, 1913.

1,084,766. Patented Jan. 20, 1914.

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UNITED STATES WALTER G. THOMAS, 0F GRASS VALLEY, CALIFORNIA.

DENTAL MALLET ANI) PLUGGEB..

Specification of Letters Patent.

Patented Jan. 20, 1914.

Application filed May 12, 1913. Serial No. 766,996.

To all whom t may concern:

Be it known that I, WALTER Gr. THOMAS, a citizen of the United States, residing at Grass Valley, in the county of Nevada and State of California, have invented new and useful Improvements in Dental Mallets and Pluggers, of which the following is a specification.

This invention relates to dental hammers and pluggers.

It is the object of this invention to provide a means in dental hammers, pluggers and similar instruments whereby the tool will have a rotary movement simultaneous with the blow or impact in a hammer, and synchronous with pressure when applied to a plugger.

In performing dental operations necessieating the use of hammers or pluggers it has been found desirable to impart a rotary movement to the instrument simultaneous with its application to the material being worked.

It is the purpose of this invention to provide means for automatically rotating the instrument which will obviate turning it by hand, and to produce a device for this purpose which is simple in construction, etticient and adapted to be applied at small cost to most types of dental hammers and pluggers now generally in use.

'Ihe invention primarily resides in providing the tool-carrying stem with a collar having a projection parallel to the stem and formed with an inclined side, and mounting a spring-pressed member within the handle of the instrument adapted to operate on longitudinal movement of the handle in relation to the stem to engage the beveled projection on the collar in such manner as to impart a rotary movement to the stem.

The invention Jfurther consists of the parts and the construction and combination of parts as hereinafter more fully described and claimed, having reference to the accompanying drawings, in which- Figure 1 is a view in vertical section partly in elevation of a well-known type of dental hammer, showing the invention as applied and in its normal position. Fig. 2 is a similariview showing the device as positioned immediately after having imparted a rotary motion to the stem. Fig. 3 is a detailed cross-section on the line a-a of Fig. 1. Fig. 4 is a detailed cross-section on the line b-b of Fig. 1. Fig. 5 is a detailed cross-section on the line c-c of Fig. l. Fig. 6 is a vertical section partly in elevation of the invention as applied to a plugger.

In the drawings the invention is shown as applied to a well-known type of dental hammer illustrated in Figs. l to 5, inclusive, and to a plugger, shown in Fig. 6.

Referring to Figs. 1 to 5, inclusive: A represents the stem of the instrument to which any suitable tool may be attached at either of its ends in the usual manner. The handle of the instrument is indicated at 2, and comprises a tubular member having a bearing 3 attached to its lower end and a cap l attached to its upper end; a bearing 5 being threaded in the upper end of the cap 4. The stem A passes through the bearings 3 and 5, and is designed to have a lengthwise and rotary movement therein. Loosely mounted on the stem A, in the handle 2, is a cylindrical hammer 6, arranged to have longitudinal movement in relation to the stem A and handle 2, and retained against rotation by means of a block 7 attached to the inner wall of the handle 2, and project ing into a longitudinally extending groove 8, formed in the hammer 6. IVound around the stem A and bearing against the upper end of the hammer G is a helical spring 9, the upper end of which bears against an adjustable sleeve 10, having a pair of oppositely disposed lugs l1 extending through vertical slots 12, adjacent to the upper end of the handle 2. The outer faces of the lugs 11 are threaded and are engaged by an internally threaded sleeve 13 revolubly mounted on the outer face of the upper ond of the handle 2; the sleeve 13 being held on the handle 9. against longitudinal movement by a shoulder 14, formed on the handle 2, against which one end of the sleeve 13 abuts, and an annular flange 1 5 on the cap 4: against which the other end ot' the sleeve 13 abuts. The sleeve 1S is designed to be rotated to cause the adjustable sleeve 10 to move up or down, and thereby vary the tension of the spring 9. Rigidly mounted on the stem A, contiguous to the end of the bearing 3, is a collar 16, formed with a circumferential channel 17, into which the hooked end 18 of a latch 19 is loosely mounted. The latch 19 extends upwardly and has an inwardly projecting lug 20 near its upper end, adapted to engage a shoulder 21 on the hammer 6 at the lower end of the groove 8; the upper end of the latch 19 extending into the groove 8 a short distance below the lower edge of the block 7. Mounted on the latch 19 is a plate spring 22, which bears against the inner wall of the handle 2 to normally retain the outer or upper end of the latch 19 in its innermost position. The upper end of the latch 19, being engaged by the groove 8 on the hammer 6, holds the latch against being rotated with the collar 16 when the latter revolves with the stem A, as will be later described; the hooked end 18 of the latch 19 being slidable in the channel 17 to permit the collar 16 moving independent of the latch. Formed on the upper face of the collar 16 is a pair of oppositely disposed projections or lugs 23, which parallel the stem A and are beveled or tapered on one edge, as at 24. Projecting downwardly from the lower end of the hammer 6 are diametrically opposite lugs' 25, which normally extend alongside of the lugs 23 and are beveled at 26 on the edges which face the beveled edges 24 of the lugs 23. Rigidly mounted on the stem A, at a point within the cap 4, is a collar 27, to which is secured one end of a helical spring 28. The helical spring 28 is wound around the stem A and has its upper end rigidly secured in a ring 29, which is securely held against movement in the cap 4 by means of the bearing 5.

When the parts are in their normal positions, as shown in Fig. 1, the hammer 6 will be subjected to the action of the spring 9, which bears between the upper end of the hammer and the adjustable sleeve 10 with a torce that is regulated by adjusting the position of the sleeve 10, by means of the sleeve 13 before described. The hammer 6 is held against downward movement in opposition to the spring 9 by means of the lug 20 on the latch 19.

In the operation of the hammer the stem A, with a suitable tool thereon, is placed against the material to be worked and is opposed thereby. The handle 2 is then moved longitudinally in relation to the stem A, thereby compressing the springs 9 and 28. When the handle 2 has been moved a short distance the lower edge of the block 7, which is beveled, will engage the upper end of the latch 26 and operate to move the latter outwardly in opposition to the spring 22, and

thereby move thevprojection 20 out of engagement with the shoulder 21. When this occurs, the spring 9 will operate to impel thel vshort distance, as the lug 25 rides over the .lug 23; the lower end of the lug 25 striking the collar 16 with considerable force and thereby transmitting a blow through the stem A to the tool. When this occurs, the parts will be positioned as shown in Fig. 2. On releasing the downward pressure on the handle 2, the latter will be restored to its normal position in relation to the stem A by the action of the spring 28, thereby causing the hammer 6 to be rengaged by the latch 19; the spring 28 also operating to rotate the stem A back to its normal position in readiness for another operation.

From the foregoing it will be seen that a rotary movement will be given the stem A simultaneous with the impact thereon of the hammer 6.

In applying the invention to pluggers wherein no impact is required on the stem A, the hammer 6 is rigidly mounted in the handle 2 against movement; the latch 19, the spring 9 and its adjustments being omitted, as shown in Fig. 6. In this form of application of the invention downward movement of the handle 2 in relation-to the stem A will transmit a rotary movement to the stem A by the action of the beveled face 26 of the lug 25 ridino' over and engaging the beveled face 24 ott the lug 28 on the collar 16. This action rotates the stem A in opposition to the torsion of the spring 28, which spring will operate on the release of the instrument to restore the stem A to its normal position.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In dental hammers and like instruments having a stem and a handle portion reciprocal in relation to the stem, a member fixed on the stem having an inclined face, and a beveled member carried by the'handle arranged to engage the member on the stem to give the latter a rotary movement on the operation of the handle.

2. The combination in a dental instrument having a stem and a handle port-ion reciprocal in relation to the stem, of a collar on the stem, a projection on said collar having an inclined face, a beveled member actuated by the reciprocation of the handle in relation to the stem, arranged to engage the my hand in the presence of two subscribing projection on the collar to transmit a rotary Witnesses.

motion to the collar and s tem in one drrection, and means for restorlng the collar and y stem to their normal positlon on the retraction of the handle in relation to the stem.

In testimony whereof I have hereunto set WALTER G. THOMAS.

Vtnesses:

C. H. BAKKER, JOSEPH FRANK.

Oopllu o! this pltent may be obtained for ve cents each, by addressing the Commhsioner ot Patenti.

' Washington, D. C. 

